Skip to main content

Profiling Slow Query in Mongodb

To monitor slow queries which are run in a mongodb database, profile attribute need to be set. There are three profiling levels: 0, 1 and 2. Add the following line into mongo.conf:
profile=1
Value 0 disables profiling. Value 1 enables the system to detect and record slow queries which take more time than given threshold value. If the attribute is set to 2, information of all queries are recorded. 

To monitor whole database, mongo.conf file could be edited. Set profile attribute to 1 or 2 and then restart mongod service :
>sudo service mongod restart.
From now on, profiling is enabled. Slow query profiling data of each database will be stored in the collection named db.system.profile.

If you don't want to monitor all databases but some, profiling level could be set for only these ones.
Select the database:
>use mydb
Set profiling level:
>db.setProfilingLevel(1)
{ "was" : 0, "slowms" : 100, "ok" : 1 }
Slowms key refers to lower time threshold value which is 100 ms as default. It could be set by giving parameter to setProflingLevel function:
>db.setProfilingLevel(1, 200)
{ "was" : 1, "slowms" : 100, "ok" : 1 }
Now, the threshold is set to 200 ms.

To clear system.profile collection, profiling needs to be stopped. Just set the level to 0. Then, call db.system.profile.remove(). Now, the collection is empty and profiling could be restarted.
Labels:
Location: Turkey

Comments

Post a Comment

Popular posts from this blog

Integration of MuPDF Project as a Library into an Android Studio Project

I have needed to use MuPDF library in my android project. After some research, I have seen that there are many integration tutorials but, but integrated projects are developed on Eclipse. For projects on AndroidStudio+Gradle, there is no example. I mean there is no specific example which exactly refers to this issue. So, after achieving my goal, I want to share the steps publicly so that it can be reused by others.
27 comments
Read more

A Way To Monetize Your Kivy Game

While I am building my game, I look for a way to monetize it. This will be my first game, so it is also the first to attempt earning money with an App. I am also not familiar to monetization companies. So, I have done a search to find an appropriate ads network which can be easily integrated with kivy . The first and only company who provides a sdk for kivy is RevMob . I integrated RevMob sdk and tested it. Unfortunately, it doesn't have a good performance and FullScreen Ads crashes. Just links will work. Therefore, RevMob option is not really preferable since ads need to be visually effective. You can also integrate android sdk of any ads network by using pyjnius . In this post, I will show how to use Adbuddiz sdk with kivy.
6 comments
Read more

Encoding multi-dimensional value into 1-D with preserving closeness

After a very long time, this will be my first post. I hope that it will not be the last, and the rest will come. For a project about taxi trajectory prediction, I have applied k-NN algorithm on coordinate sequence of taxi trips. Did I have promising results? Well, it is arguable, but I have discovered some good techniques. One of them is Z-order curve (Figure 1). Figure 1: Four levels of Z-ordering (taken from Wikipedia  page) I was looking for a technique to decrease dimensionality of 2-D coordinate representation (lat-lon) into 1-D . But on this 1-D value, I would like to apply k-NN algorithm. For this purpose, 1-D values must preserve the closeness of two different coordinates. If I do linear ordering of latitude and longitude values, I couldn't achieve this goal, because closeness will depend on only one value which is placed on the right-most. Let's assume I do linear ordering as lat-lon:
11 comments
Read more